The present invention relates to a method for achieving accurate measurement of the true weight of a load, and in particular, it concerns achieving the accurate measurement of true weight by use of a weight measuring device in conjunction with a load bearing structure, the load bearing structure having the ability to be tilted by the operator, such as, but not limited to, a scale which is built into a forklift truck, or being tilted as a result of natural occurrences, such as the tipping of a ship, which is caused by waves.
It is known that much of the shipping in the world today is done using pallets as transportation platforms. A loaded pallet may be moved using various types of pallet carriers or forklift devices, usually having one or two tines, which are inserted under the pallet. These forklift devices can be equipped with a built-in scale for weighing the loads on the pallet. Scales for this purpose utilize load cells, which measure the forces applied to them in a direction of measurement. The tines or carrying platform of a forklift truck may be tilted by the operator for purposes of stability.
It is further known that some loads have to be transported in a level position, and some loads have a limited tolerance for change in the angle of transportation. This would be true of loads which are very tall, or of containers whose contents may shift and cause instability. In many cases, these limited tolerances are impossible to judge by sight, and may be too small to be monitored by a device such as a spirit level, which works well for determining xe2x80x9clevel,xe2x80x9d but whose unit of measure beyond that, is inappropriate.
It is further known that in order for a weighing scale to accurately measure the weight of an object, it must be level, that is to say, perfectly horizontal. The scale must be level because, if the load cell is at an angle to the vertical forces applied to it, only the component of the force being applied in the load cell""s direction of measurement (the force x the cosine of the angle) will be measured.
There is further known a scale that utilizes inclinometers and a processor in conjunction with a load cell. The processor uses information from the load cell (amount of force) and the inclinometers (angle of load from horizontal) to determine the true weight of the load. While effective, this scale incurs added cost as a result of the added inclinometers and may suffer reliability problems due to the number of complex components.
There is therefore a need for a method that can achieve accurate measurement of true weight without the need for dedicated inclination measuring elements, thereby rendering the system simpler, more reliable and cheaper, and that can accurately determine and display the angle of a load at any given time as it is being transported.
The present invention is a method for achieving accurate measurement of the true weight of a load.
According to the teachings of the present invention, a weight measuring device is used in conjunction with a load bearing structure.
According to a further teaching of the present invention, the load bearing structure is configured so as to tilt the plane that is represented by the top surface of the weight measuring device about an axis referred to as the xe2x80x9cprimary axisxe2x80x9d, such as, but not limited to, a load bearing structure of a forklift truck, which has a built-in scale.
According to a further teaching of the present invention, the load bearing structure is tilted as a result of natural occurrences, such as the tipping of a ship, which are caused by waves.
According to a further teaching of the present invention, the plane is tilted about the primary axis through a range of angles of inclination so that a line in the plane, which is perpendicular to the primary axis, passes through horizontal.
According to a further teaching of the present invention, the load force data obtained by the weight measuring device during the tilting process is sent to a processor unit.
According to a further teaching of the present invention, the true weight of the load is calculated using the highest load force reading received from the weight measuring device.
According to a further teaching of the present invention, prior to tilting the plane about the primary axis, the plane is rotated about a second axis referred to as the xe2x80x9csecondary axis,xe2x80x9d which is perpendicular to the primary axis, until a line in the plane, which is perpendicular to the secondary axis, is brought to horizontal, and the resulting highest load force reading is the true weight of the load.
According to an alternate teaching of the present invention, the inclination of the plane, in relation to horizontal about the secondary axis, is measured by use of an inclinometer and the resulting data is used, in conjunction with the data from the weight measuring device, to calculate the true weight of the load.
According to a further teaching of the present invention, the data is sent to the processor, during the tilting process, at a rate that is fast enough to obtain all necessary load force data.
According to a further teaching of the present invention, the true weight is displayed by means of a display unit.
According to a further teaching of the present invention, the subsequent inclination of the plane is determined as a function of the true weight and the subsequent data from the weight measuring device.
Additionally, according to a further teaching of the present invention, there is provided a method for determining the angle of inclination of a load that is being supported by a weight measuring device in conjunction with a load bearing structure.
According to a further teaching of the present invention, an accurate measurement of the true weight of the load is obtained.
According to a further teaching of the present invention, the current load force data from the weight measuring device is sent to a processor.
According to a further teaching of the present invention, the angle of the load is calculated as a function of the current load force data and the true weight of the load.
According to a further teaching of the present invention, the accurate measurement of the true weight of the load is obtained while the load is positioned on the weight measuring device allowing the necessary load force data to be sent directly to the processor.
According to a further teaching of the present invention, the accurate measurement of the true weight of the load is measured prior to positioning the load on the weight measuring device, and the true weight data is manually entered into the processor.
According to a further teaching of the present invention, the angle of inclination is displayed by means of a display unit.
Additionally, according to a further teaching of the present invention, there is provided a method for achieving accurate measurement of true weight of a load, using a weight measuring device in conjunction with a load bearing structure, the load bearing structure being in a state of motion so as to tilt the plane that is represented by the load bearing surface of the weight measuring device about a primary axis, the method comprising: placing the load on the weight measuring device; sending load force data, which is obtained by the weight measuring device as the plane tilts about the primary axis through a range of angles of inclination so that a line in the plane that is perpendicular to the primary axis passes through horizontal, to a processor unit; and calculating the true weight of the load using the highest value of the load force data received from the weight measuring device.
According to a further teaching of the present invention, the state of motion is a result of waves, which cause the tipping movement of a ship.
According to a further teaching of the present invention, the inclination of said plane, in relation to horizontal, about a secondary axis is measured by use of an inclinometer, the resulting data being used, in conjunction with the load force data from the weight measuring device, to calculate the true weight of the load.
According to a further teaching of the present invention, the data is sent to the processor substantially continuously.
According to a further teaching of the present invention, the true weight is displayed by means of a display unit.
According to a further teaching of the present invention, subsequent inclination of the plane is determined as a function of the true weight and subsequent data from the weight measuring device.